Tree nut consumption: preventing cardiovascular disease
The first studies to provide us with proof of the favourable effect of tree nuts on health were carried out in large cities. Most of them concentrated on the possible relationship between tree nut consumption and cardiovascular disorders such as myocardial infarction or angina pectoris. The first study published in this area was the Adventist Health Study (1992), carried out on a group of Adventists in California. The study involved a sample of 31,208 Caucasian Adventists, whose diet habitually included tree nuts. Higher tree nut consumption was seen to be associated with a low risk of cardiovascular illness. Thus, after six months of monitoring, those individuals who regularly consumed tree nuts five times a week of more displayed a lower risk of non-fatal myocardial infarction (51% less than non-consumers). Subsequent observational studies which were also conducted on Adventist populations showed similar results. These studies, carried out by the same team, showed that those individuals with a high tree nut consumption had a greater life expectancy without coronary episodes, as well as proving once again that the risk of cardiovascular illness was lower in population groups with high tree nut consumption. Other, more recent studies have yielded similar results. Thus, in the Iowa Women's Health Study (1996) 34,486 post-menopausal women were monitored over seven years. The aim of the study was to observe the relationship between antioxidant consumption (dietary or in the form of supplements) and cardiovascular mortality. The authors discovered an inverse relationship between vitamin E consumption and the risk of death due to coronary illness, a much stronger link when the vitamin E came from dietary sources rather than supplements. Given that tree nuts are one of the major dietary sources of vitamin E, an inverse relationship was also observed between cardiovascular mortality and tree nut consumption. Those women who consumed tree nuts four or more times a week ran a 40% lower risk of death due to coronary illness than those who did not consume tree nuts. The Harvard Nurse's Health Study (1998) examined the connection between nut consumption and the risk of coronary illness over a fourteen-year period using 86,016 nurses between 34 and 59 years of age. It was observed that the women who took five or more portions of tree nuts a week (one portion being 28 grams net weight) showed a lower risk of suffering coronary illness than the women who never ate tree nuts or those who took less than one portion a month. The study carried out by Lavedrine in France, with 793 men and women between 18 and 65 years of age also assessed the connection between tree nut consumption, in this case walnuts, and various cardiovascular risk factors. The authors found that those individuals who regularly consumed walnuts displayed higher concentrations of HDL cholesterol (good cholesterol). The recent Physician's Health Study produced similar results to those described above. In comparison with those who never or rarely consumed tree nuts, the individuals who had tree nuts twice or more a week displayed a lower risk of cardiac sudden death and lower total cardiovascular mortality. On the basis of the observed data from these studies, dietary intervention studies were begun, that is, studies in which the participants were provided with tree nuts and the effects of their consumption upon various cardiovascular risk factors was observed.,In the majority of studies the results were positive, corroborating that tree nut consumption is associated with a lowering of total and LDL (bad) cholesterol levels.Nucis (Health and Tree Nuts) Foundation is a non profit organisation born in 1999, headquartered in Spain, which main objectives are the study, investigation and the diffusion of the nutritional and dietetic characteristics of tree nuts, especially of the healthy beneficial effects. Nucis promotes the healthy qualities of almonds, Brazil walnuts, cashews, hazelnuts, macadamias, pecans, pine kernels, pistachios and walnuts. More information in http://www.nucis.org
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Spain